1. Field of the Invention (Technical Field)
The invention relates to communication systems, and more particularly to a wireless communication apparatus and method for the simultaneous displaying of broadcast information by visual and audio means of performances both live and recorded on multiple channels whereby each channel can contain text in a language as selected by the user.
2. Background Art
The current state of the art for displaying translations is well described in U.S. Pat. No. 5,739,869 to Markle, et al. There are some limitations of the method and apparatus described therein. The invention described in U.S. Pat. No. 5,739,869 presents a method of distributing multiple channels of information to multiple users. This new invention provides a means to overcome the shortcomings of the Markle patent. A wireless means of transmitting data was described in U.S. Pat. No. 5,739,869 but no details were provided. It is well known to those familiar with electromagnetic transmission of data, that there is a high probability that the transmitted data will be corrupted during transmission. Various means exist to detect and correct such corruption. First, the frequency used to transmit can be selected so that there are no other sources of similar frequency operating within the broadcast area. Spread spectrum transmission means well known to those practiced in the art is another way of attaining clear and reliable transmission of data. Even with these two highly effective means of avoiding interference, it is still likely that corruption can occur. The method commonly used to ensure that data is received correctly is to retransmit the data. This requires two-way communications and a communication protocol, of which there are many possible types described and well known to those familiar with the art. Two-way communications are not practical in this application because of the large bandwidth required, the complicated protocol and the cost of the implementation, particularly with large installations comprising several thousand receivers.
Data correction methods are sometimes used to repair the damaged data transmission. These methods use several transmissions of the data and then apply a comparison of the received data to determine which transmission of the several received is correct. This method has a high statistical probability of detecting burst errors, but cannot detect and correct all errors. It is likely that errors in transmission will be passed along. In audio applications this is not a problem because the small errors passed will probably not be noticed in the whole transmission. These small errors are a problem with transmitted data because the characters presented will contain spurious errors which are readily detected by the users. It is therefore possible that the corruption of the data could change the presented text in such a way that an inappropriate meaning is conveyed. It is not possible to provide data correction of high enough certainty without drastically increasing bandwidth or transmission and processing time, and so is not a feasible alternative for this application. If a receiver does receives corrupt or incomplete data it can request that the information be retransmitted. This procedure becomes extremely complicated when many receivers request retransmission and requires a high bandwidth transmission medium to handle the requests. If a receiver is not aware that data has been transmitted because the whole transmission was missed, then it cannot request a retransmission of the data.
The present invention describes a method of achieving reliable low cost retransmission of data using low bandwidth one-way data transmission to many receivers. The method identifies each packet of data to be transmitted with a unique identifier. The packet then has a CRC (cyclic redundancy check) calculated and appended to the packet. This complete packet is transmitted and received by the individual devices. If the unique identifier is different to the one packet received previously, then the display device proceeds as follows. If the identifiers are identical then the transmission is ignored. The individual display devices then calculate another CRC using the received data and if the received and calculated CRC""s are identical, then the data can be reliably declared as correct and the display device can then process the data. If the CRC""s are not identical, then an error has occurred in transmission. The device or devices that received corrupted data discard that data and wait for the next transmission. If only corrupted data is received then nothing is presented by the display module, instead of displaying incomplete or mangled data that causes more problems.
The addition of batteries and wireless data transmission means allows the device to be portable. This has many advantages, to install the system in an existing house no power and data wires need be installed, this saves significant cost when installing the system.
The main problem with a xe2x80x9chard-wiredxe2x80x9d installation is that the whole installation needs to be installed at one time, the necessary construction work required, and the installation time needed indicates that the space cannot be used for performances while the installation is occurring. Some buildings are protected by a historic building covenant and any changes to the fabric of such buildings are prohibited. There is considerable cost involved in retrofitting such a system to an existing building, as the structure, design, layout, construction methods, and fittings are often not compatible with the later installation of such a system. Avoiding such installation work saves significant time and money
Another problem with such xe2x80x9chard-wiredxe2x80x9d installations is that it is economic only to install the system in one operation. The purchasers of such a system need to pay for the installation of the complete system at one time as staging the installation is much more expensive and time consuming. A wireless installation allows for an installation to proceed in stages, the system being fully operational but not necessarily complete at any one time. The wireless system allows for partial installations where a number of people are free to sit at any location in the house, something not possible with a xe2x80x9chard-wiredxe2x80x9d installation. The number of display units can be increased at any time as demand or finances permit.
When a hard-wired system is installed in a newly constructed system, significant savings can be realized with the inclusion of the necessary system installation work and components into the buildings construction schedule. Due to the nature of the system, much of the installation can only be performed after the other trades involved in the construction have completed their work. This means that the overall construction time must be extended to allow for the system installation to be completed before the building can be opened. This scheduling problem is extremely difficult to solve without increasing the cost of the building installation. A wireless installation can occur during the last stages of the buildings construction without affecting the building schedule.
U.S. Pat. No. 4,438,432, to Hurcum, discloses an information display system which uses multiplexed data which is transmitted over wires. This system uses addresses to decode transmitted data.
U.S. Pat. No. 4,361,848, to Poignet, discloses a tele-text method of displaying text on television using control characters. The system uses a keyboard to access information and does not support live performance use.
U.S. Pat. No. 5,850,416, to Myer, teaches a wireless, transmitter-receiver information device which uses no batteries, and utilizes an inductive power transfer method, whereby the power to operate the display unit is superimposed on the data signal. The system makes no mention of live performances, multiple channels or simultaneous display of multiple channels.
U.S. Pat. No. 5,896,129, to Murphy, shows an interface for an interactive flight entertainment system for passengers with special needs. The described system is a method for guiding a user though a long series of required key-stokes to access their selection from a wide range of choices. One of those options is closed captioning which is already well known to those familiar with the art, and audio captioning for the hearing impaired. The system described is a method of selection of such choices but fails to describe how such choices are transmitted.
In another embodiment of the invention the display output is limited to one character, and in very large size. One or more of these single character embodiments can then be arranged to produce a large multi-character display of any size or configuration. Economies of production are realized because the individual single character embodiments are much smaller than a complete sign capable of displaying multi-character text, and therefore less expensive and easier to manufacture. This xe2x80x9cmodular designxe2x80x9d approach allows for different configurations to be used. Each single character embodiment has a different xe2x80x9cChannelxe2x80x9d selected and only receives data which is identified as being for that specific channel. Several of these large multi-character assemblies can be used, all displaying the same information or different information such as translations into other languages.
In accordance with the present invention, there is provided a wireless apparatus and method for simultaneously displaying a selected channel of data to a remote site. The preferred apparatus comprises a portable multi-channel apparatus for the storing, transmitting, and simultaneous displaying of at least one selected channel to a remote site without any connecting wires. The preferred apparatus is battery powered and the data is transmitted by electromagnetic radiation. The data is sent from a main control unit to a transmitter that then broadcasts the data. The portable multi-channel apparatus can then receive the transmitted data and display it, as instructed by the user.
The transmitted data package preferably comprises a packet header, unique packet identifier, a header for at least one channel, an end of message instruction for the at least one channel, a data integrity verification means, and an end of packet identifier. The data packets are continually rebroadcast at regular intervals by the main control unit and transmitter. The receipt of the at least one display of the next data packet with a different unique packet identifier causes the display to verify that the data package is correctly received, and if so, overrides the stored data in the buffer, otherwise the display ignores that received transmission and waits for the next transmission where the process is repeated. This ensures that the data received, processed, and displayed is identical to the data transmitted from the main control unit without the complication of bi-directional communications. In the event of an incomplete or corrupted transmission receipt, the display waits for another transmission. The data packets can also comprise at least one reserved character to control display brightness, image brightness, and image display time. The main control unit comprises an apparatus for selecting the at least one predetermined portion of the preselected sequence of text.
The preferred system utilizes the UNICODE method of encoding characters, giving access to all character sets for all written languages.
The apparatus for distributing data comprises at least one transmitter and at least one receiver. The data is transmitted by electromagnetic radiation means.
The primary object of the invention is a portable display unit that presents a channel of information to view, describing a performance to audience members either individually or to a group.
Another object of this invention is to provide a scalable system that may be partially or completely installed or expanded at any time. Installation work would cause minimal disturbance to the building and environment.
Yet another object of this invention is to have the capacity to present any written language at any time.
Yet another object of the invention is to provide the choice of the transmitting frequency which can be changed for use in other countries or where existing equipment is already installed and would not cause interference.
The primary advantage of the present invention is that the installation of the system causes minimal disturbance to the environment, power and data wires do not need to be installed in the installation site.
Another advantage is that the system can be portable for use in touring productions whereby the invention can be set up quickly and easily in different locations and be assured that the system is available for use for that production.
Another advantage of the portable system is that it is scalable, that is, it can be partially installed and made operational and then at a future date be expanded as needs require or funding becomes available. In this way immediate compliance with disabled persons legislation is possible.
Another advantage is that people with disabilities have access to visual or audio information.
Another advantage of the system is that it is possible to use it in outdoor locations. Such usage would include outdoor concerts and performances, multi-cultural events, stadium events, sporting events, religious services, and such events.
Another advantage of the system is that by using a localized transmission medium it is possible to transmit in a limited area. The system can be used in applications such as galleries or museums where there are many exhibits in many rooms. Transmitters could be placed near exhibits and transmit information about such exhibit or all the exhibits in an area. As the patron enters the transmission zone their display would receive the data for the nearest exhibit and display it in the language selected. Thus as the patron moved about the gallery or museum, their display would, in a timely manner, present information about the nearest exhibits.
Another advantage of the system is that by using a wide-ranging transmission medium it is possible to transmit to a large area, comprising multiple buildings or large geographic zones.
Another advantage of the system is that there is no limit to the number of units that can simultaneously operate. Additional transmitters may be required to cover the necessary area depending on the space and transmission medium used.
Another advantage of the invention is that because it is powered by battery, it can operate independently and does not need a power distribution means to be installed at the point of use.
Another advantage of the invention is that because it receives its data by electromagnetic radiation, it operates independently and does not require cables to be installed at the point of use.
Another advantage of the system is that by utilizing the UNICODE character set, every unit is capable of displaying any written language. Multiple variations of the unit are not required for different countries and all languages are available on every display if required. Other written graphic information such as symbolic representation of sign language for the deaf can also be implemented.
Another advantage of the system is that complex formatting of the displayed text is achieved by special formatting codes. These special formatting codes allow the text to be positioned anywhere on the screen while still retaining the text information in compact character code form. This has the advantage of containing the data in very a compact form, and thus reduces the amount of data that would need to be transmitted if a graphic bitmapped scheme was employed.
Another advantage of this invention is the redundant transmission of the data packets. If a display unit does not receive a complete data packet the device waits for the next transmitted packet. After receiving a packet the device ignores all future rebroadcasts of the data until a new data packet is detected. This means that there might be a small delay in presenting the text if the reception of a data packet is missed because of interference or obscuring of the signal; however, once clear communication is established, the display unit would function normally without complex and costly two-way communications.
Other objects, advantages and novel features, and further scope of applicability of the present invention will be set forth in part in the detailed description to follow, and taken in part will become apparent to those skilled in the art upon examination of the following, or may be learned by the practice of the invention. The objects and advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out in the appended claims.